Traditionally, sausages have been prepared by extruding sausage paste or meat into a prepared sausage casing. Such casings have usually been prepared from sheep or pig intestines, regenerated cellulose or regenerated collagen. This method of preparation is particularly disadvantageous because there is no way to continuously stuff a prepared food casing. As a result, stuffing of prepared food casings is a batch operation. More recently, this problem has been overcome by coextruding a collagen gel or other casing material along with the sausage paste, and the collagen gel hardens to form the sausage casing.
It is often desirable to smoke the sausage product to impart a smokey flavor and color into the product. The above-described coextrusion method has been used in connection with sausage products that are smoked by treating the products with liquid smoke. Typically liquid smoke is applied to the surface of the sausage product either by showering, atomizing or spraying. Another method of using liquid smoke is to blend it directly into the sausage product, although this methods tends to cause artificially harsh smoke flavors and often fails to impart the most desired smoke color to the surface of the food product. Another disadvantage of liquid smoke is that it tends to be corrosive and, if not applied properly, causes inconsistent flavor and color.
Alternatively, a sausage product can be smoked by treating the product with natural smoke. Natural smoke provides a better smoke flavor to the sausage product than does liquid smoke. However, natural smoke also has disadvantages. Notably, if the outer surface of a sausage product is not completely dry before the natural smoke is applied, the sausage will have a muddy color instead of the desired mahogany color. Additionally, in typical flat belt ovens, the bottom and top surfaces of the sausage dry at different rates and to different extents, so that uniform application of the natural smoke cannot be achieved, thereby resulting in a non-uniform smoky color. Another problem with typical flat belt ovens is that it can be difficult to produce a sausage having a consistent round shape because the surface of the sausage that sits on the belt tends to flatten. Further, the surface of the belt on which the sausage rests creates touch marks on the sausage, which are often undesirable to the consumer. Also, the surface of the sausage is not uniformly exposed to heat, chilled air and cooling showers.
In addition, cellulose casing must be peeled from the product before packaging, creating a large quantity of waste material. Natural casing or regenerated collagen casing products require a process to separate the links from a string of products before packaging. The links separation is labor intensive and can, under some circumstances, result in micro contamination.
Accordingly, a need exists for an improved method for producing sausage whereby the sausage paste can be introduced into the casing using a fully-automated process. The sausage can be treated with natural smoke to achieve the desired smoke color and flavor. The resulting product can have a round shape as well as minimal or substantially no micro contamination.
The present invention is directed to a method and apparatus for producing sausage. The inventive method and apparatus can overcome the above drawbacks and produce a round sausage having the desired color and less contamination using a fully-automated system. The invention also minimizes the potential for touch marks on the sausage by transporting the sausages in baskets that change orientation during heating.
In one embodiment, the invention is directed to a method for making sausages. The method comprises coextruding sausage paste and collagen to form a continuous sausage body having an outer tube comprising collagen in surrounding relation to the sausage paste. The continuous sausage body is then separated into individual sausage links, each having an exterior surface The sausage links are transported to an enclosure to be heated and smoked. The sausage links are loaded into baskets on an endless belt contained at least in part within the enclosure. The belt can be caused to circulate along a serpentine path so that the sausage links are carried boustrophedonically by the baskets through the enclosure. The baskets can thus be caused to successively change their orientations rotationally as the belt circulates within the enclosure so that different parts of the exterior surface of each sausage link come successively into contact with a concave interior surface of the basket in which that sausage link is carried. Heat is supplied to a selected portion of the enclosure to cook the sausage links. Additionally, the sausage links can be treated with natural smoke in a selected portion of the enclosure.
Another aspect of the invention is directed to an apparatus for processing sausages that are elongated and approximately round in cross-section. The apparatus comprises a coextruder that, in use, is capable of coextruding sausage paste and collagen to form a continuous elongated sausage body having an outer tube comprising collagen in surrounding relation to the sausage paste; means for separating the continuous sausage body into individual sausage links downstream of the coextruder, preferably a crimping device; an enclosure downstream of the separating means; an endless serpentine belt formed in part by a series of generally similar elongated baskets, each oriented generally perpendicular to the direction of travel of the serpentine belt and being capable of changing its orientation rotationally relative to other baskets, each basket having a concave interior surface and a longitudinal opening through which sausage links can enter and exit, and each basket being dimensioned to contain at least one sausage link; one or more conveyor belts for transporting the sausage links between the separating means and the serpentine belt; a plurality of idlers and drive members and at least one motor arranged to cause the serpentine belt to circulate boustrophedonically within the enclosure; a heater for raising the temperature within at least part of the enclosure to cook the sausage links as they are carried by the serpentine belt; and a natural smoke generator to smoke the sausage links as they are carried by the serpentine belt in the enclosure.